1. Field of the Invention
The present invention relates generally to networking. More particularly, the present invention relates to layer 2 (typically, ethernet) networking.
2. Description of the Background Art
Designing and implementing high-availability Ethernet LAN topologies in industrial networks is challenging. While ring and mesh topologies are coming into more general use, finding practical ways to provide for recovery from faults for edge devices and nodes is difficult. While devices such as computers can be configured with two NICs for dual connections into the network, the software is complex. For industrial sensors and controllers, very few PLCs and IEDs are designed by their manufacturer to be equipped with such a feature. In addition, the serial field buses that have been traditionally used for industrial control do not offer fault-tolerant options, and industrial systems designers are not accustomed to planning for redundancy for control devices. The choices have been too limited and too expensive and too complicated to be considered in most industrial systems.